build: include LICENSE in gateway-builder image

Stage the repo-root LICENSE into /app/LICENSE for the gateway-builder
image, matching the pattern already used by gateway-runtime,
gateway-controller, and event-gateway-runtime.

- Add target/ build-context with LICENSE for both build and
  build-and-push-multiarch targets.
- Place at /app/LICENSE (consistent with other images); /workspace is
  reserved for user policy projects mounted at runtime.
- Gitignore the new gateway-builder/target/ directory.

Author: renuka-fernando

.gitignore

@@ -142,6 +142,7 @@ platform-api/src/resources/openapi_with_binding.yaml
 # Gateway
 gateway/gateway-runtime/target
 gateway/gateway-controller/target/
+gateway/gateway-builder/target/
 event-gateway/gateway-runtime/target/
 dev-policies/
 

gateway/gateway-builder/Dockerfile

@@ -97,6 +97,7 @@ COPY --from=system-policies . /api-platform/gateway/system-policies
 COPY --from=common . /api-platform/common
 COPY --from=sdk-core . /api-platform/sdk/core
 COPY --from=sdk-python . /api-platform/sdk-python
+COPY --from=target LICENSE /app/LICENSE
 
 # Set working directory
 WORKDIR /workspace

gateway/gateway-builder/Makefile

@@ -56,6 +56,8 @@ help: ## Show this help message
 .PHONY: build
 build: ## Build Docker image using buildx
 	@echo "Building Docker image ($(IMAGE_NAME):$(VERSION))..."
+	@mkdir -p target
+	@cp ../../LICENSE target/
 	@docker buildx build -f Dockerfile \
 		--build-context policy-engine=../gateway-runtime/policy-engine \
 		--build-context python-executor=../gateway-runtime/python-executor \
@@ -64,6 +66,7 @@ build: ## Build Docker image using buildx
 		--build-context sdk-core=../../sdk/core \
 		--build-context sdk-python=../../sdk-python \
 		--build-context common=../../common \
+		--build-context target=target \
 		--build-arg VERSION=$(VERSION) \
 		--build-arg GIT_COMMIT=$(GIT_COMMIT) \
 		-t $(IMAGE_NAME):$(VERSION) \
@@ -81,6 +84,8 @@ push: ## Push Docker image to registry
 .PHONY: build-and-push-multiarch
 build-and-push-multiarch: ## Build and push multi-architecture Docker image (linux/amd64, linux/arm64)
 	@echo "Building and pushing multi-arch Docker image: $(IMAGE_NAME):$(VERSION)"
+	@mkdir -p target
+	@cp ../../LICENSE target/
 	docker buildx build -f Dockerfile \
 		--build-context policy-engine=../gateway-runtime/policy-engine \
 		--build-context python-executor=../gateway-runtime/python-executor \
@@ -89,6 +94,7 @@ build-and-push-multiarch: ## Build and push multi-architecture Docker image (lin
 		--build-context sdk-core=../../sdk/core \
 		--build-context sdk-python=../../sdk-python \
 		--build-context common=../../common \
+		--build-context target=target \
 		--platform linux/amd64,linux/arm64 \
 		--build-arg VERSION=$(VERSION) \
 		--build-arg GIT_COMMIT=$(GIT_COMMIT) \